Process for producing esters



United States Patent M 3,476,797 PROCESS FOR PRODUCING ESTERS Joseph B.Mettalia, Jr., Southampton, and Edward H. Specht, Huntingdon Valley,Pa., assignors to Rohm & Haas Company, Philadelphia, Pa., a corporationof Delaware No Drawing. Filed Aug. 22, 1966, Ser. No. 573,799 Int. Cl.C07c 69/66, 69/52 US. Cl. 260-484 7 Claims ABSTRACT OF THE DISCLOSUREThis invention relates to a method for the preparation of alkyl7-hydroxy-2,S-heptadienoates and dialkyl 2,5,8- decatriene-1,10-dioatesby the reaction of 2-butene-1,4- diol, acetylene, nickel carbonyl,carbon monoxide, an alkanol of one to eight carbon atoms, an acid, and ahalide, where the acid is an organic acid of one to eight carbon atoms,phosphoric acid, phosphorous acid, or

boric acid, and the halide is a bromide or iodide of the alkali metals,lithium chloride, or the iodide of the alkaline earth metals.

present invention are the alkyl 7 -hydroxy- 2,5 -heptadienoates, thealkyl portion depending directly on the alkanol employed in thereaction. These esters have known utilities, for instance, to formpolyesters and polyamides, whichare useful as films or fibers. They mayalso be hydrogenated to form the corresponding saturated ester orfurther reacted under the circumstances of the present invention to formdialkyl 2,5,8-decatriene-1,10-dioates which have known utilities,particularly in the fiber field, such as for garments, tires and others.

Many attempts have been made in the prior art to produce the alkyl7-hydroxy-2,5-heptadienoates and dialkyl 2,5,8-decatriene-1,10-dioates.Various degrees of success have been reported but all previous attemptshave been plagued by substantial competing reactions which inevitablylead to large amounts of undesired side products or no reaction at all.By rigidly adhering to the teachings of the present invention, oneconsistently achieves good yields of desired product.

The alkanols used in the present process are those containing from oneto eight carbon atoms and may be straight or branched chain in any ofthe known spatial configurations. It is preferred to use the loweralkanols, such as from one to four carbon atoms and especially methanol.Typically, there may be employed methanol, ethanol, isopropanol,butanol, hexanol, Z-ethylhexanol, octanol and the like. It is preferredto employ methanol or ethanol.

In addition to 2-butene-1,4-diol, which is the preferred reactant, theremay be employed 2,3-dialkyl substituted 2-butene-l,4-diols. These alkylsubstituents should contain no more than four carbon atoms each,preferably one to two carbon atoms. It is possible to havejust 'onealkyl substituent. These alkyl embodiments include methyl, ethyl, propylor butyl. With the propyl or butyl em- Patented Nov. 4, 1969 bodiments,it is preferred to employ the straight chain configurations.

The acid employedincludes organic acids of one to eight carbon atoms,such as formic, acetic, butanoic, octanoic, benzoic and the like. Therealso may be employed phosphoric acid, phosphorous acid and bo'ric acid.The preferred acid is phosphoric. In this respect, it is emphasized thatstrong acids, such as hydrochloric and sulfuric acids, do not reactaccording to the teachings of the present process.

To conduct the reaction of the present invention, one adds, as desired,the various defined reactants, preferably substantially simultaneously.In some instances, it is preferable to react the 2-butene-1,4-dio1 withthe defined acid to form a diester and then continue the reaction withthe remainder of the defined reactants. Such a modification is withinthe gamut of this invention.

The halide employed comprises the bromides and iodides of the alkalimetals, lithium chloride and the iodides of the alkaline earth metals.Typically, these include sodium iodide, sodium bromide, potassiumiodide, potassium bromide, lithium chloride, lithium iodide, lithiumbromide, calcium iodide, barium iodide and strontium iodide. Thepreferred embodiments are calcium iodide, lithium chloride,lithiumbromide and sodium bromide...

The present reaction is conducted at a temperature of 25 to 75 C.,preferably 40 to C. Atmospheric pressure is perfectly satisfactoryalthough increased pressures may be employed, if desired.

The halide is employed in the range of 0.01 mole per mole of the diol to1.0 mole per mole of the diol, preferably 0.05 to 0.20 mole per mole ofthe diol.

The acetylene is employed in the range of 0.3 mole per mole of diol to3.5 moles per mole of the diol,,preferably 1.0 to 2.0 moles per mole ofthe diol.

The acid is employed'in the range .of 0.2 mole per mole of diol to 2.0moles per mole of the diol, preferably 0.3 to 0.7 mole per mole of thediol.

The nickel carbonyl is employed in the range of 0.25 mole per mole ofthe diol to 1.0 mole per mole of th diol.

Carbon monoxide is supplied to the reaction system entirely orprincipally, as desired,- through the agency of nickel carbonyl.

In many instances, carbon monoxide gas, in addition to the carbonmonoxide supplied-by the nickel carbonyl, is advantageouslyadded to thereaction system. lnqsuch instances, there may be, employed amountsup toabout 0.8, preferably 0.5 to 0,,75, moleofcarbonmonoxide per mole of thediol.

During the course of the present reaction, both alkyl 7- hydroxy 2,5heptadienoate and dialkyl 2,5,8 decatriene 1,10 dioate are formed. Theformation of the monoester is favored by shorter reaction times and theuse of the lower molar ranges of acid, acetylene and is, reduced. Theuseof longerreaction.times and higher molar amount of acid, acetylene andhalide favors a higher yield of the diester and a higher total yield ofproducts.

- At the conclusion of the reaction, the product (both monoester anddiester) is isolated by stripping unused, volatile reactantsandextracting the remainder with a suitable ex'tractant, such as diethyletherand, water. The product is found in the ether layer, which-may thenbe isolated by standard distillation -ftechniqu es,-. preferably underreduced pressure. f if.

The present process may be merc fully understood from the followingexamples, which are offered by, way of illustration and not by way oflimitation. r f f A solution of 44 g. (0.5 mole) 2-butene-1,4-diol and29.4 g. phosphoric acid (aqueous 86%, 0.3 mole) made up to 240 cc. withmethanol was charged to a 1-liter 4 EXAMPLE 3 A solution of 0.12 moleLiBr in 250 cc. anhydrous ethanol was charged to l-liter reactor. Thetemperature was held at 55 C, while a total of 0.6 mole of 1,4 di- ITrifluoroacatic acid.

continuous flow stirred tank reactor. The reactor was 5 flushed withnitrogen and maintained at 45 C. A solua-ceqaxy-gbut-ene (prepared.prehmmanly by ieactmg tion of NKCO) in methanol was fed 'at a mm of 31acet1c ac1d w1th 2-butene-l,4-d1ol), 0.4 mole of N1(CO) 4 mole/hour ofNi(CO) and a solution of NaBr in metha- 56 2 2 g gfi i g ii z E: 512 3;grxg f ig i 1101 was fed at -a rate of 0.27 mole/ hour of NaBr.Initially, S f acetylene and carbon monoxide were fed at 0 56 mole/ andNl(co).'4 were stripped under reduced pres' hour and 0.14 mole/hour,respectively. After the reaction sure and the resldile extfacted withether fi Water The had initiated (as evidenced b an exotherm and theether layer was dried w1th Na SO and stripped of ether. a earance of ared color) theiilarious feeds were main The residue could not bedistilled without decomposition. gg at the following rats Ni(co) at 0 31m mom Pure product was isolated, however, from a preparative igas-liquid chromatograph. Diethyl 2,5-8- decatriene-1,10- Eiifhfiifii.Z3;151322;.ffiffilfisiifi'dfi1332 53.3 35 gfi g g g g g- H 0 (66 hour,Phosphoric acid at 0.31 m./hour and methanol at th (7 3 & f 957 m./hour.The reaction was maintained for eight hours g t 1 a e ry a at which timea sufiicient number of reactor volume turn- 1 is c almef 18 v E 1k 1 7 hd overs had occurred to ensure obtaining an equilibrium 20 procfass or te Preparanon o a y foxy sample for workup. The material in the reactorwas haiptadlnoate and decamen? I filtered, stripped of Ni(CO) andmethanol under reduced dloate 1n whlch h alkyl i from one to elghtpressure, and the residue extracted with ether and water. ig g g fifi g?i 2535 5? g i g Analysis of the aqueous layer showed 0.15 mole of 0Ni++/O 5 mole butenediol reacted. The ether layer was 25 moles ofacetylene per mole of said d1ol, about 0.25 to dried with Na SO filteredand distilled under reduced 1110,16 of mckel carbonyl Per {nole of salddlo carbon pressure to give two major products. The first was methyl g gg a 1 122 3? :5 2:5 gsg ggig z?zgg gi 7 hydroxy 2,5 heptadienoate, B.P.90 C. 21 1.4870, O a identical in infrared and NMR spectra with anauthentic {mole of F Z mole of f sample prepared by a different routeand which gave the wherem said ac1d is an orgamc ac1d of one to eightcarfollowing elemental analysis: calculated for C H O C hon P F P P,bonc aclds (61 4 theory 52% H (757% theory 7 75%) wherem sald halide 1sa bromlde or iodide of the alkali metals, lithium chloride or the iodideof the alkaline and O (31.25%, theory 30.73%). The second product th tls was dimeth 1 2,5,8 decatn'ene 1,10 dioate, B.P. 0.1 ear me a vmm o 201.4396, i f d Spectrum (liquid 2. The process according to cla1m 1wherein the resmear): strong bands at 1715 to 1730 cmr 1435 cmraction isconducted w1th1n the range of about to 60 1400 emf- 968 cm." and 815cmr' C. and there are employed:

Analysis.-Calculated for C I-1 0 C (64.35%, about 0.05 to 0.20 mole ofsaid hahde per mole of theory 64.27%), H (7.32%, theory 7.19%) and O 40the diol,

( theory 28.54%). about 1.0 to 2.0 moles of said acetylene per mole of Asample was hydrogenated to give, after purification, the di l,

a compound identicahwith dimethyl sebacate. The first about 03 to 7 molef Said i per mole f the product was obtamed 1n 29% converslon and thesecond diol, and

m 34% converslon both basgd on the 'butenedlol' about 0.25 to 1.0 moleof said nickel carbonyl per mole EXAMPLE 2 of the diol.

A series of experiments was performed in which a 3. The processaccording to claim 1 wherein there 1s solution of 0.95 mole2-butene-1,4-diol in 300 cc. of emPloyed up to flbout mole of carbon,monoxlde gas methanol was charged to a one-liter reactor. Separate Pmole of the d101- f d f halide i Ni(c()) acetylene carbon 4. The processaccord ng to cla1m 1 wherem said alimoxide and additional methanol werethen maintained for r101 18 methanol, s'ald ac1d -p p n and said halidea period of 1 to 2 hours. The results are given in the is lithiumbromide. table. 5. The process according to claim 1 wherein said alka-TABLE Runs Halide Cal: LiCl LiBr NaI NaBr Halide (moles fed) 0. 2a 0.620.10 0. 23 0. 23 Acid HaP04 Acid (moles red).-." 0. 00 1.08 1.50 1.80 1.so -Ni(CO) (m oles fed) 0.56 0. 40 0. 42 0.43 0.40 Acetylene (moles fed)2. 75 2. 70 2. 70 1. 46 2. 70 Carbon monoxide (moles fed) 0. 63 0.20 0.65 0. 60 Methanol (cc. led) 300 300 300 300 300 Temperature C.) 45 45 35Percent Conversion (on butenediol) Methyl 7-hydr0xy-2,5heptadienoate 0.50 5. 00 1.00 0. 02 4. 00 Di methyl 2,5,8-decatrieue-L10-dioate..-.56.00 1.00 50. 00' 51.00 53.00

' Formic acid;

I Benzoic acid.

nol is ethanol, said acid is phosphoric and said halide is 2,882,2984/1959 Luberoif 260-486 sodium bromide. 3,110,725 11/ 1963 Chiusoli260-486 XR 6. The process according to claim 1 wherein said 3,146,2568/1964 Chiusoli 260485 XR alkanol is methanol, said acid is benzoic andsaid halide 3,236,879 2/1966 Chiusoli 260-484 is sodium iodide. 53,238,246 3/1966 Chiusoli et al 260-486 7. The process according toclaim 1 wherein said 3,312,731 4/1967 Chiusoli et al 260-485 alkanol ismethanol, said acid is phosphoric and said halide is calcium iodide.JAMES A. PATTEN, Primary Examiner References Cited 10 ALBERT P. HALLUIN,Assistant Examiner UNITED STATES PATENTS U.S. C1. X.R.

2,599,424 6/1952 Albrecht et a1. 260-486 XR 269-485 2,613,222 10/1952Specht et a1 260L-486XR

